Atropine pharmaceutical compositions

ABSTRACT

The inventive subject matter is directed to compositions and methods for sterile and storage stable low-dose atropine formulations with improved stability. Most preferably, the compositions presented herein are substantially preservative free and exhibit less than 0.35% tropic acid from degradation of atropine. Advantageously, contemplated formulations are also substantially free of preservatives.

This application is a divisional application of allowed US applicationwith the Ser. No. 15/976,279, which was filed May 10, 2018, and whichclaims priority to US provisional application with the Ser. No.62/505,027, which was filed May 11, 2017.

FIELD OF THE INVENTION

The field of the invention is pharmaceutical compositions comprisingatropine sulfate, especially as it relates to various storage stable,ready-to-use, preservative free compositions, and method ofmanufacturing such compositions.

BACKGROUND

The background description includes information that may be useful inunderstanding the present invention. It is not an admission that any ofthe information provided herein is prior art or relevant to thepresently claimed invention, or that any publication specifically orimplicitly referenced is prior art.

All publications and patent applications herein are incorporated byreference to the same extent as if each individual publication or patentapplication were specifically and individually indicated to beincorporated by reference. Where a definition or use of a term in anincorporated reference is inconsistent or contrary to the definition ofthat term provided herein, the definition of that term provided hereinapplies and the definition of that term in the reference does not apply.

Atropine is the tropine ester of tropic acid and is generally availableas the sulfate salt. Nonenzymatic spontaneous hydrolysis of aqueousatropine yields tropine and tropic acid that are nontoxic but do nothave biological activity in ophthalmic use. Stability has been tested,for example, for certain injectable formulations and degradation wasobserved over time for in-date and out-of-date formulations (Acad EmergMed April 2004, Vol. 11, No. 4:329-334). Notably, atropine loss wassignificant in most cases, but less than 25% of the startingconcentration. However, these formulations included atropine at highconcentrations between 0.4 mg/ml and 2 mg/ml and had a very low pH(typically equal or less than pH4), which is in most cases unsuitablefor ophthalmic use.

In ophthalmic use, atropine is marketed as Atropine Care (Akorn)formulated as a 1% drug solution for treatment of amblyopia and furthercontains 0.01% w/w of the preservative benzalkonium chloride. In anotherindication, atropine has also been used in several pediatric studies toslow down the progression of myopia. More specifically, children whoreceived topically administered atropine drops had a slower diseaseprogression than a control group in the same study. Advantageously,children receiving eye drops containing low atropine concentrations(e.g., in the range of 0.01-0.05%% w/v (0.01% w/w)) had significantlyless photophobia and other side effects (see e.g., Ophthalmology,2015:1-9). Indeed, the use of low-dose (i.e., 0.01%) atropine has becomea preferred treatment of choice in slowing the progression of myopia.Unfortunately, the toxic effects of benzalkonium chloride have beendemonstrated in the lab and in the clinic, and include tear filminstability, loss of goblet cells, conjunctival squamous metaplasia andapoptosis, disruption of the corneal epithelium barrier, and damage todeeper ocular tissues (see e.g., Prog Retin Eye Res. 2010 Jul.29(4):312-34).

In still further known compositions and methods, atropine formulationsare described in WO 2017/204262 that include various buffer ingredientsand water soluble polymers in which most formulations had a pH of about4.3, 4.5, or 5.0 at an atropine concentration of 0.01% w/w. While suchformulations were shown to reduce progression of myopia withoutexacerbating mydriatic action of atropine, stability of atropine asmeasured by an increase in tropic acid was less than desirable within aslittle as four weeks.

As normal tears have a pH of about 7.4, an ophthalmic solution shouldhave the same pH as the lacrimal fluid. However, this is a challenge foran ophthalmic solutions containing atropine sulfate, as atropine sulfateis subjected to a greater degree of hydrolysis in solutions that arecloser to neutral and basic pH conditions. Thus, atropine is more stablein ophthalmic solutions with a more acidic pH. For example, AtropineCare with a 1% w/w concentration of atropine is maintained at pH 5.5,but the shelf life is still limited to 15 months. Moreover, thedegradation of atropine to tropic acid in aqueous solution is notablyaccelerated with reduced concentrations of atropine (e.g., U.S. Pat. No.9,421,199), which still further compounds stability issues, particularlyin low-dose atropine formulations.

To reduce hydrolytic degradation, water in low-dose atropineformulations can be at least in part replaced with deuterated (heavy)water as is described in the U.S. Pat. No. 9,421,199 patent. Whileconceptually attractive to use kinetic isotope effects in stability,various disadvantages nevertheless remain. Among other things, at leastsome of the formulations of the '199 patent still contained apreservative. Moreover, deuterated water is still known to be subject toH/D exchange, and as such delivers deuterium to a subject receiving suchformulations.

Alternatively, atropine may also be delivered at reduced concentrationsfrom a cross-linked non-degradable polymer matrix as is described in US2016/0338947. Unfortunately, to maintain the polymer away from thecornea, a shaped implant must be worn on the sclera that is typicallynot well tolerated or may produce discomfort.

Therefore, there is a need for improved storage stable ready-to-usecompositions that contain atropine at low concentrations, have aphysiologically desirable pH, and preferably do not contain apreservative.

SUMMARY OF THE INVENTION

The inventive subject matter is directed to ready-to-use atropinecompositions having improved stability and a physiologically acceptablepH. Most preferably, such compositions are also substantiallypreservative free.

In one aspect of the inventive subject matter, the inventors contemplatea liquid storage-stable low-dose ophthalmic atropine composition thatcomprises an aqueous solution comprising a buffer, a tonicity agent, aviscosity modifier, and atropine or a pharmaceutically acceptable saltthereof, wherein the atropine or the pharmaceutically acceptable saltthereof is present in the ophthalmic atropine composition in an amountof equal or less than 0.05 wt %, wherein the buffer has a concentrationof equal or less than 75 mM, and wherein the ophthalmic atropinecomposition has a pH of between 5.0 and 6.0, and wherein the ophthalmicatropine composition is formulated such that after storage over at leasttwo months at 25° C. and 60% relative humidity equal or less than 0.35%tropic acid is formed from degradation of the atropine.

Preferably, atropine or the pharmaceutically acceptable salt thereof isatropine sulfate, and is present in the ophthalmic atropine compositionin an amount of equal or less than 0.02 wt %, or in an amount of equalor less than 0.01 wt %, or in an amount of between 0.01% and 0.05 wt %,or in an amount of between 0.001 wt % and 0.01 wt %. Most typically, thebuffer has a concentration of equal or less than 60 mM, or equal or lessthan 50 mM. It is further contemplated that the buffer comprisesmonobasic and dibasic sodium phosphate. In further embodiments, thecomposition will further comprise a chelator, typically a bicarboxylicacid, a tricarboxylic acid, or an aminopolycarboxylic acid, and thechelator is present in the ophthalmic atropine composition in an amountof equal or less than 0.01 w %.

Additionally, it is contemplated that the ophthalmic atropinecomposition has a pH of 5.0 (+/−0.2), or has a pH of 5.5 (+/−0.2), orhas a pH of 6.0 (+/−0.2). The tonicity agent is preferably apharmaceutically acceptable salt that is present in the ophthalmicatropine composition in an amount of between 0.2 wt % and 0.8 wt %. Instill further embodiments, the viscosity modifier is a modifiedcellulose, and preferably a hydroxyethyl cellulose, a hydroxypropylcellulose, or a hydroxypropyl methylcellulose. Moreover, it is generallypreferred that the ophthalmic atropine composition is substantially freeof a preservative.

Therefore, the inventors also contemplate a liquid storage-stablelow-dose ophthalmic atropine composition that consists essentially of anaqueous solution comprising a buffer, a tonicity agent, a chelator, aviscosity modifier, and atropine or a pharmaceutically acceptable saltthereof. In such compositions it is preferred that the atropine or thepharmaceutically acceptable salt thereof is present in the ophthalmicatropine composition in an amount of equal or less than 0.05 wt %, thatthe buffer has a concentration of equal or less than 75 mM, and that theophthalmic atropine composition has a pH of between 5.0 and 6.0.Moreover, such ophthalmic atropine compositions are formulated such thatafter storage over at least two months at 25° C. and 60% relativehumidity equal or less than 0.35% tropic acid is formed from degradationof the atropine.

Most typically, the atropine or the pharmaceutically acceptable saltthereof is atropine sulfate, and the atropine or a pharmaceuticallyacceptable salt thereof is present in the ophthalmic atropinecomposition in an amount of equal or less than 0.02 wt %, or in anamount of equal or less than 0.01 wt %, or in an amount of between 0.001wt % and 0.01 wt %. In some embodiments, the buffer has a concentrationof equal or less than 60 mM, or has a concentration of equal or lessthan 50 mM. it is further contemplated that the buffer comprisesmonobasic and dibasic sodium phosphate. The chelator is typically abicarboxylic acid, a tricarboxylic acid, or an aminopolycarboxylic acid.For example, suitable chelators include ethylenediaminetetraacetic acid(EDTA), typically present in the ophthalmic atropine composition in anamount of equal or less than 0.01 wt %.

In other embodiments, the ophthalmic atropine composition has a pH ofbetween 5.0 (+/−0.2) and 5.5 (+/−0.2), or has a pH of between 5.5(+/−0.2) and 6.0 (+/−0.2), and/or the tonicity agent is apharmaceutically acceptable salt that is present in the ophthalmicatropine composition in an amount of between 0.2 wt % and 0.8 wt %.Suitable viscosity modifiers include a hydroxyethyl cellulose, ahydroxypropyl cellulose, and a hydroxypropyl methylcellulose. Mosttypically, the ophthalmic atropine composition is substantially free ofa preservative.

For example, contemplated compositions include those in which theatropine or a pharmaceutically acceptable salt thereof is present in theophthalmic atropine composition in an amount of between 0.001 wt % and0.01 wt %, wherein the buffer comprises monobasic and dibasic sodiumphosphate and has a concentration of equal or less than 50 mM, whereinthe viscosity modifier is a hydroxyethyl cellulose, a hydroxypropylcellulose, or a hydroxypropyl methylcellulose, and wherein theophthalmic atropine composition is substantially free of a preservative.In other examples, contemplated compositions include those in which theatropine or a pharmaceutically acceptable salt thereof is present in theophthalmic atropine composition in an amount of between 0.01 wt % and0.05 wt %, wherein the buffer comprises monobasic and dibasic sodiumphosphate and has a concentration of equal or less than 50 mM, whereinthe viscosity modifier is a hydroxyethyl cellulose, a hydroxypropylcellulose, or a hydroxypropyl methylcellulose, and wherein theophthalmic atropine composition is substantially free of a preservative.

Viewed from a different perspective, the inventors also contemplate astorage-stable preservative-free ophthalmic atropine composition thatcomprises an aqueous solution comprising low-dose atropine or apharmaceutically acceptable salt thereof, a low-strength buffer, apharmaceutically acceptable salt, and a cellulosic viscosity modifier,wherein the low-strength buffer has a concentration of equal or lessthan 50 mM, and wherein the low-dose atropine is present at aconcentration of equal or less than 0.05 wt %, and wherein theophthalmic atropine composition is substantially free of a preservative.

For example, the low-dose atropine in such compositions is present at aconcentration of equal or less than 0.01 wt %, or is present in theophthalmic atropine composition in an amount of between 0.01% and 0.02wt %, or is present in the ophthalmic atropine composition in an amountof between 0.001 wt % and 0.01 wt %. Most typically, the atropine or apharmaceutically acceptable salt thereof is atropine sulfate, and/or thelow-strength buffer comprises a first and a second buffer component(e.g., monobasic and dibasic sodium phosphate). Most typically, theophthalmic atropine composition has a pH of between 5.0 and 6.0, or a pHof between 5.5 (+/−0.2) and 6.0 (+/−0.2). Contemplated compositions willtypically also include a chelator (e.g., a bicarboxylic acid, atricarboxylic acid, an aminopolycarboxylic acid) that is preferablypresent in an amount of 0.01 wt % (+/−20% abs.). It is furthercontemplated that the pharmaceutically acceptable salt is present in theophthalmic atropine composition in an amount of between 0.2 wt % and 0.8wt %, or in an amount of 0.5 wt % (+/−0.2 wt %).

Preferred cellulosic viscosity modifiers include a hydroxyethylcellulose, a hydroxypropyl cellulose, or a hydroxypropylmethylcellulose, typically present in an amount of 0.5 wt % (+/−0.1 wt%) of the ophthalmic atropine composition. In preferred embodiments, theophthalmic atropine composition is formulated such that after storageover at least two months at 25° C. and 60% relative humidity equal orless than 0.35% tropic acid is formed from degradation of the atropine.

For example, in contemplated compositions the atropine or apharmaceutically acceptable salt thereof is present in the ophthalmicatropine composition in an amount of between 0.001 wt % and 0.01 wt %,wherein the low-strength buffer comprises monobasic and dibasic sodiumphosphate, and wherein the ophthalmic atropine composition has a pH ofbetween 5.5 (+/−0.2) and 6.0 (+/−0.2). In another example, the atropineor a pharmaceutically acceptable salt thereof is present in theophthalmic atropine composition in contemplated compositions is presentin an amount of between 0.001 wt % and 0.01 wt %, wherein the ophthalmicatropine composition further comprises a chelator in an amount of 0.01wt % (+/−20% abs.) of the ophthalmic atropine composition, and whereinthe ophthalmic atropine composition has a pH of between 5.5 (+/−0.2) and6.0 (+/−0.2). Alternatively, the low-strength buffer in contemplatedcompositions comprises monobasic and dibasic sodium phosphate, whereinthe composition further comprises a chelator in an amount of 0.01 wt %(+/−20% abs.) of the ophthalmic atropine composition, wherein theophthalmic atropine composition has a pH of between 5.5 (+/−0.2) and 6.0(+/−0.2), wherein the salt is present in the ophthalmic atropinecomposition in an amount of 0.5 wt % (+/−0.2 wt %), and wherein thecellulosic viscosity modifier is present in an amount of 0.5 wt %(+/−0.1 wt %) of the ophthalmic atropine composition.

In still another aspect of the inventive subject matter, the inventorsalso contemplate a method of increasing storage stability of atropine ina liquid low-dose ophthalmic formulation. Typical low-doses are between0.01 wt % and 0.02 wt %, or between 0.001 wt % and 0.01 wt %, or equalor less than 0.01 wt % of the ophthalmic formulation. Preferred methodswill include a step of formulating an aqueous solution with alow-strength buffer system that includes a first and second buffercomponent, wherein the low-strength buffer system has a concentration ofequal or less than 75 mM buffer, and a further step of including intothe aqueous solution a pharmaceutically acceptable salt, a viscositymodifier, and a chelator. In still another step, atropine or apharmaceutically acceptable salt thereof is included into theformulation at a low dose (e.g., equal or less than 0.05 wt % of theophthalmic formulation), and the pH of the ophthalmic formulation isadjusted to a pH between 5 and 6. Preferably, the ophthalmic formulationis formulated such that after storage over at least two months at 25° C.and 60% relative humidity equal or less than 0.35% tropic acid is formedfrom degradation of the atropine.

For example, the first and second buffer components are monobasic anddibasic sodium phosphate, respectively, and the low-strength buffersystem has a concentration of equal or less than 50 mM buffer.Additionally, it is contemplated that the pharmaceutically acceptablesalt is sodium chloride, typically present in the ophthalmic atropinecomposition in an amount of 0.5 wt % (+/−0.2 wt %) of the ophthalmicformulation. Moreover, it is preferred that the chelator is abicarboxylic acid, a tricarboxylic acid, or an aminopolycarboxylic acid(e.g., EDTA), preferably in an amount of 0.01 wt % (+/−20% abs.) of theophthalmic formulation.

In other embodiments, the viscosity modifier is a cellulosic viscositymodifier, such as a hydroxyethyl cellulose, a hydroxypropyl cellulose,or a hydroxypropyl methylcellulose. Most typically the cellulosicviscosity modifier is present in an amount of 0.5 wt % (+/−0.1 wt %) ofthe ophthalmic formulation. In still further embodiments, the cellulosicviscosity modifier is prepared as a separate solution, and combined withthe aqueous solution containing the buffer system, the pharmaceuticallyacceptable salt, the viscosity modifier, the chelator, and the atropineor the pharmaceutically acceptable salt thereof. Where desired, theaqueous solution is formulated using deoxygenated water. Most typically,the pH of the formulation is between 5.5 (+/−0.2) and 6.0 (+/−0.2), andthe atropine or a pharmaceutically acceptable salt thereof is atropinesulfate. Preferably, contemplated methods also include a step ofsterilizing the ophthalmic formulation, and especially sterilefiltration. As desired, the ophthalmic formulation is then filled into asingle-use or multi-dose container.

Additionally, the inventors also contemplate a method of preparing astorage stable liquid low-dose atropine ophthalmic formulation thatincludes the steps of formulating in a first container a low-strengthbuffer low-dose atropine solution, and subjecting the low-strengthbuffer low-dose atropine solution to sterile filtration to obtain asterile low-strength buffer low-dose atropine solution, wherein thelow-strength buffer has a first and a second buffer component that forma low-strength buffer system having a concentration of equal or lessthan 75 mM in the ophthalmic formulation, wherein the atropine ispresent in an amount of equal or less than 0.05 wt % of the ophthalmicformulation, and wherein the low-strength buffer low-dose atropinesolution further comprises a tonicity agent and a chelator. In anotherstep, a polymer solution is formulated in a second container, and thepolymer solution is sterilized in a process other than sterilefiltration (e.g., autoclaving) to so obtain a sterile polymer solution.Most typically, the polymer solution comprises a polymer to modifyviscosity of the low-strength buffer low-dose atropine solution uponcombination. In yet another step, the sterile low-strength bufferlow-dose atropine solution and the sterile polymer solution are combinedto obtain a sterile liquid low-dose ophthalmic formulation.

Typically, the first and second buffer components are monobasic anddibasic sodium phosphate, respectively, and/or the low-strength buffersystem has a concentration of equal or less than 50 mM buffer in theophthalmic formulation. The atropine is typically present in an amountof between 0.01 wt % and 0.02 wt %, or between 0.001 wt % and 0.01 wt %,or equal or less than 0.01 wt % of the ophthalmic formulation. Mostpreferably, the tonicity agent is a pharmaceutically acceptable salt,typically sodium chloride in an amount of 0.5 wt % (+/−0.2 wt %) of theophthalmic formulation. Moreover, the chelator is typically abicarboxylic acid, a tricarboxylic acid, or an aminopolycarboxylic acid(e.g., EDTA), preferably in an amount of 0.01 wt % (+/−20% abs.) of theophthalmic formulation.

It is still further contemplated that the polymer is a cellulosicpolymer, and especially a hydroxyethyl cellulose, a hydroxypropylcellulose, or a hydroxypropyl methylcellulose. Preferably, thecellulosic polymer is present in an amount of 0.5 wt % (+/−0.1 wt %) ofthe ophthalmic formulation, and/or the pH of the low-strength bufferlow-dose atropine solution is adjusted to a pH between 5 and 6, orbetween 5.5 (+/−0.2) and 6.0 (+/−0.2).

In further embodiments, the step of combining comprises mixing thesterile low-strength buffer low-dose atropine solution and the sterilepolymer solution for at least 30 minutes, and optionally furthercomprises a step of filling the ophthalmic formulation into a multi-dosecontainer. Preferably, the ophthalmic formulation is formulated suchthat after storage over at least two months at 25° C. and 60% relativehumidity equal or less than 0.35% tropic acid is formed from degradationof the atropine.

Consequently, the inventors also contemplate a treatment kit fortreatment of myopia that includes a first container that contains aliquid storage-stable low-dose atropine ophthalmic formulation, whereinthe first container is configured as a disposable single-use containeror a multi-dose container, and a second container enclosing the firstcontainer, wherein the liquid storage-stable low-dose atropineophthalmic formulation comprises an aqueous solution comprising abuffer, a tonicity agent, a viscosity modifier, and atropine or apharmaceutically acceptable salt thereof, wherein the atropine or thepharmaceutically acceptable salt thereof is present in the ophthalmicatropine composition in an amount of equal or less than 0.05 wt %,wherein the buffer has a concentration of equal or less than 75 mM, andwherein the ophthalmic atropine composition has a pH of between 5.0 and6.0, and wherein the ophthalmic atropine composition is formulated suchthat after storage over at least two months at 25° C. and 60% relativehumidity equal or less than 0.35% tropic acid is formed from degradationof the atropine.

For example, in some embodiments, the first container is ablow-fill-seal (BSF) container and/or the second container is alaminated metallized pouch. In other embodiments, the atropine orpharmaceutically acceptable salt thereof is present in the ophthalmicatropine composition in an amount of equal or less than 0.01 wt %, or inan amount of between 0.01 wt % and 0.05 wt %, or in an amount of between0.001 wt % and 0.01 wt %. Most preferably, the buffer has aconcentration of equal or less than 75 mM, or equal or less than 50 mM.For example, preferred buffers comprise monobasic and dibasic sodiumphosphate, and may further comprise a chelator (e.g., a bicarboxylicacid, a tricarboxylic acid, or an aminopolycarboxylic acid such as EDTA)that is present in the ophthalmic atropine composition in an amount ofequal or less than 0.01 wt %.

Most typically, the ophthalmic atropine composition has a pH of 5.0(+/−0.2), or a pH of 5.5 (+/−0.2), or a pH of 6.0 (+/−0.2), and it isfurther contemplated that the tonicity agent is a pharmaceuticallyacceptable salt that is present in the ophthalmic atropine compositionin an amount of between 0.2 wt % and 0.8 wt %. Preferred viscositymodifiers are modified celluloses such as a hydroxyethyl cellulose, ahydroxypropyl cellulose, or a hydroxypropyl methylcellulose. Stillfurther, it is preferred that the ophthalmic atropine composition issubstantially free of a preservative.

Various objects, features, aspects and advantages of the inventivesubject matter will become more apparent from the following detaileddescription of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts an exemplary production process for the storage stableand low-dose atropine ophthalmic formulation.

DETAILED DESCRIPTION OF THE INVENTION

The inventive subject matter is directed to stable aqueous ophthalmiccompositions of atropine (and pharmaceutically acceptable salts thereof)in a ready-to-use form that are sterile and preferably substantiallyfree of preservatives. The stability of contemplated compositions ischaracterized by low degradation of atropine to tropic acid at lowatropine concentrations, as well as by a physiologically desirable pH.For example, liquid and storage-stable low-dose ophthalmic atropinecompositions will typically have stability upon storage over at leasttwo months at 25° C. and 60% relative humidity such that equal or lessthan 0.35% tropic acid is formed by the degradation of atropine in theformulation. Most preferably, the compositions are also free ofpreservatives, and particularly benzalkonium chloride that is commonlyused as a preservative. Such stability is particularly unexpected wherethe atropine concentration in the ophthalmic composition is relativelylow (e.g., 0.02 wt %) and where the composition has a relatively high pH(e.g., between 5.0 and 6.0) as it was generally known that atropinestability decreases at decreasing concentrations and increasing pH.

While not wishing to be bound by any particular theory or hypothesis,the inventors contemplate that low buffer strength using a two-componentbuffer system at a pH near to a neutral pH (such as pH 5.0-6.0) reduceshydrolysis of atropine to tropic acid where atropine concentrations arerelatively low (e.g., equal or less than 0.05 wt %, or equal or lessthan 0.02 wt %, or equal or less than 0.01 wt %). Unless indicatedotherwise, all percentages are weight percentages (wt %) or expressed asweight by volume (w/v). Moreover, it is noted that weight percentages ofatropine sulfate provided herein are based on atropine sulfatemonohydrate.

More specifically, and as is described in more detail below, theinventors discovered that low-dose ophthalmic atropine compositions canbe prepared with atropine in a ready-to-use concentration (e.g., fortreatment of myopia) that have a near-physiological pH, and thatpreferably lack any preservative in the formulation. Surprisingly, thestorage stability at two months at 25° C. and 60% RH of the ophthalmiccompositions presented herein is remarkably high, with tropic acidformation from atropine hydrolysis in most cases at or below 0.35%, ator below 0.30%, or at or below 0.28%. Similarly, contemplatedformulations at accelerated storage conditions over two months at 40° C.and 75% RH also exhibited an equally favorable profile with tropic acidformation in most cases at or below 1.7%, at or below 1.5%, at or below1.3%, or at or below 1.2%.

Therefore, contemplated atropine formulations of the inventive subjectmatter can be advantageously provided in a ready-to-use format thatavoids the inconvenience associated with diluting concentrated atropineformulations into diluents prior to administration. Thus, theready-to-use formulations also eliminate microbial contamination risksand/or calculation errors associated with dilution. Most typically,contemplated formulations will be available in a range of concentrationscommonly required by medical practitioners for treatment of myopia, andparticularly pediatric myopia. Consequently, atropine will typically bepresent in formulations in an amount of equal or less than 0.05 wt %, orin an amount of equal or less than 0.02 wt %, or in an amount of equalor less than 0.01 wt %. For example, the atropine or a pharmaceuticallyacceptable salt thereof may be present in the ophthalmic composition inan amount of between 0.01% and 0.05 wt %, between 0.001 wt % and 0.02 wt%, or between 0.001 wt % and 0.01 wt %. As will be readily appreciated,atropine for the preparation of contemplated formulations may beatropine or any suitable pharmaceutically acceptable salt thereof,including mineral salts (e.g., HCl salt) and organic salts (e.g.,sulfate). Similarly, where desired, the atropine may also be used in anysuitable prodrug form.

For example, in one exemplary embodiment, the concentration of atropinein contemplated atropine formulations is from about 0.001% to about0.05% (w/w); or from about 0.005% to about 0.045% (w/w), or from about0.006% to about 0.035% (w/w), or from about 0.007% to about 0.030%(w/w), or from about 0.008% to about 0.025% (w/w), or from about 0.009%to about 0.022% (w/w), or from about 0.01% to about 0.021% (w/w) or fromabout 0.01% to about 0.02% (w/w).

In another exemplary embodiment, the concentration of atropine incontemplated atropine formulations is from about 0.001% to about 0.05%(w/w); or from about 0.005% to about 0.045% (w/w), or from about 0.006%to about 0.035% (w/w), or from about 0.007% to about 0.030% (w/w), orfrom about 0.008% to about 0.025% (w/w), or from about 0.009% to about0.022% (w/w), or from about 0.01% to about 0.021% (w/w) or from about0.01% to about 0.02% (w/w).

In still an exemplary embodiment, the concentration of atropine incontemplated atropine formulations is about 0.001%, or about 0.002%, orabout 0.003%, or about 0.004%, or about 0.005%, or about 0.006%, orabout 0.007%, or about 0.008%, or about 0.009%, or about 0.01%, or about0.011%, or about 0.012%, or about 0.013%, or about 0.014%, or about0.015%, or about 0.016%, or about 0.017%, or about 0.018%, or about0.019%, or about 0.02%, or about 0.021%, or about 0.022%, or about0.023%, or about 0.024%, or about 0.025%, or about 0.026%, or about0.027%, or about 0.028%, or about 0.029%, or about 0.030%, or about0.031%, or about 0.032%, or about 0.033%, or about 0.034%, or about0.035%, or about 0.036%, or about 0.037%, or about 0.038%, or about0.039%, or about 0.040%, or about 0.041%, or about 0.042%, or about0.043%, or about 0.044%, or about 0.045%, or about 0.046%, or about0.047%, or about 0.048%, or about 0.049% or about 0.0499% (w/w).

In yet an exemplary embodiment, the concentration of atropine incontemplated atropine formulations is about 0.001%, or 0.002%, or0.003%, or 0.004%, or 0.005%, or 0.006%, or 0.007%, or 0.008%, or0.009%, or 0.01%, or 0.011%, or 0.012%, or 0.013%, or 0.014%, or 0.015%,or 0.016%, or 0.017%, or 0.018%, or 0.019%, or 0.02%, or 0.021%, or0.022%, or 0.023%, or 0.024%, or 0.025%, or 0.026%, or 0.027%, or0.028%, or 0.029%, or 0.030%, or 0.031%, or 0.032%, or 0.033%, or0.034%, or 0.035%, or 0.036%, or 0.037%, or 0.038%, or 0.039%, or0.040%, or 0.041%, or 0.042%, or 0.043%, or 0.044%, or 0.045%, or0.046%, or 0.047%, or 0.048%, or 0.049% or 0.0499% (w/w).

In further exemplary embodiments, the concentration of atropine incontemplated atropine formulations is from about 0.005% to about 0.015%(w/w), or from about 0.015% to about 0.025% (w/w), or about 0.01% (w/w),or about 0.02% (w/w), or from 0.005% to 0.015% (w/w), or from 0.015% to0.025% (w/w), or 0.01% (w/w), or 0.02% (w/w), or from about 0.001% (w/w)to about 0.01% (w/w), or from about 0.005% (w/w) to about 0.02% (w/w),or from about 0.008% (w/w) to about 0.012% (w/w).

Suitable buffers are generally buffers that stabilize the pH of thecontemplated liquid formulations in a near-neutral pH range, for examplebetween pH 4.0 and 7.5, or between pH 4.5 and 6.5, and more preferablybetween pH 5.0 and 6.0. Therefore, and most typically the pH ofcontemplated formulations will be equal or less than 6.5 and moretypically equal or less than 6.0, and most typically less than 5.8, buthigher than 4.5, more typically higher than 5.0, and most typicallyhigher than 5.2. For example, suitable atropine compositions may have apH of 5.0 (+/−0.2), or a pH of 5.5 (+/−0.2), or a pH of 6.0 (+/−0.2).

In further aspects of the inventive subject matter, the inventorsdiscovered that the buffer system and/or buffer may have an unexpectedinfluence on atropine stability as is discussed in more detail below.Most notably, once the buffer concentration was adjusted to 75 mM orless at a pH of between 5.0-6.0, the stability of the atropinedramatically increased at normal and accelerated storage conditions asdetermined by HPLC quantification of tropic acid that is a byproduct ofatropine hydrolysis. While not limiting to the inventive subject matter,the buffer strength is typically relatively low, for example, equal orless than 100 mM, equal or less than 75 mM, equal or less than 60 mM,equal or less than 50 mM, or between 5 mM and 50 mM (e.g., 10 mM, 20 mM,30 mM, 40 mM).

Therefore, in exemplary embodiments, the buffering system is in thepharmaceutical composition in a concentration of from about 10 mM toabout 75 mM, or from about 10 mM to about 60 mM, or from about 0.1 mM toabout 60 mM, or from about 0.1 mM to about 55 mM, or from about 0.1 mMto about 50 mM, or from about 5 mM to about 60 mM, or from about 0.1 mMto about 10 mM, or from about 1 mM to about 10 mM, or from about 9 mM toabout 20 mM, or from about 15 mM to about 25 mM, or from about 19 mM toabout 29 mM, or from about 24 mM to about 34 mM, or from about 29 mM toabout 39 mM, or from about 34 mM to about 44 mM, or from about 39 mM toabout 49 mM, or from about 44 mM to about 54 mM, or from about 19 mM toabout 54 mM, or from about 25 mM to about 54 mM.

Of course, it should be appreciated that there are many types of buffersystems and buffers known in the art, and all of those are deemedsuitable for use herein, including buffer systems comprising an acid anda salt of the acid, a first and a second salt (e.g., monobasic anddibasic salt), and amphoteric buffer molecules. For example, suitablebuffer systems with an acid and a salt of the acid include citricacid/sodium citrate buffers, ethanoic acid/sodium ethanoate buffers,boric acid/sodium borate, while suitable buffers having a first and asecond salt include monobasic sodium phosphate/dibasic sodium phosphate,or monobasic sodium phosphate/sodium citrate, etc. Similarly, suitableamphoteric buffer molecules include HEPES, MOPS, PIPES, MES, etc.

Moreover, in further contemplated aspects, the formulation will alsoinclude one or more chelating agents, and particularly metal ionchelators. For example, suitable chelators include various bicarboxylicacids, tricarboxylic acids, and aminopolycarboxylic acids such asethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(β-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA), andpenta(carboxymethyl)diethylenetriamine (DTPA), and salts and hydratesthereof. While not limiting to the inventive subject matter, it iscontemplated that the metal ion chelators will slow down both thebaseline and metal ion-stimulated hydrolysis of atropine. Remarkably,the inventors unexpectedly observed that the desirable effect of thechelators was observable at relatively low concentrations of thechelators. For example, reduction of the baseline and metalion-stimulated hydrolysis of atropine was observed at chelatorconcentrations of between 10 μg/ml and 50 μg/ml, between 50 μg/ml and250 μg/ml, and between 100 μg/ml and 500 μg/ml. Viewed form a differentperspective, chelator concentrations of equal or less than 0.03 wt %, orequal or less than 0.02 wt %, or equal or less than 0.01 wt % areespecially advantageous. Interestingly, the chelators, and especiallythe aminopolycarboxylic acids retained stabilizing effect at lowconcentrations despite the relatively low pH favoring protonated formsof the chelators.

Consequently, suitable chelating agents include monomeric polyacids suchas EDTA, cyclohexanediamine tetraacetic acid (CDTA),hydroxyethylethylenediamine triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), dimercaptopropane sulfonic acid (DMPS),dimercaptosuccmic acid (DMSA), aminotrimethylene phosphonic acid (ATPA),citric acid, ophthalmologically acceptable salts thereof, andcombinations of any of the foregoing. Further suitable chelating agentsinclude pyrophosphates, tripolyphosphates, and, hexametaphosphates,chelating antibiotics such as chloroquine and tetracycline,nitrogen-containing chelating agent containing two or more chelatingnitrogen atoms within an imino group or in an aromatic ring (e.g.,diimines, 2,2′-bipyridines, etc.), and various polyamines such as cyclam(1,4,7,11-tetraazacyclotetradecane), N—(C₁-C₃₀ alkyl)-substitutedcyclams (e.g., hexadecyclam, tetramethylhexadecylcyclam),diethylenetriamine (DETA), spermine, diethylnorspermine (DENSPM),diethylhomo-spermine (DEHOP), and deferoxamine(N′-[5-[[4-[[5-(acetylhydroxyamino)pentyl]amino]-1,4-dioxobutyl]hydroxy-amino]pentyl]-N′-(5-aminopentyl)-N-hydroxybutanediamide;also known as desferrioxamine B and DFO).

With respect to suitable salts it is contemplated that the salt is apharmaceutically acceptable salt that can be used to increase tonicity.Therefore, pharmaceutically acceptable salts are contemplated, andespecially NaCl, at a concentration of at least 0.2 wt %, or at least0.4 wt %, or at least 0.5 wt %, or at least 0.7 wt %. For example,suitable salt concentrations are between 0.2 wt % and 1.1 wt %, 0.4 wt %and 0.9 wt %, or 0.3 wt % and 0.7 wt %. Depending on the particular saltconcentration, additional tonicity agents may be added and suitabletonicity agents include glycerol, thioglycerol, mannitol, lactose, anddextrose. The amount of tonicity adjusting agent used can be adjusted toobtain osmolality of the formulations in the range of 260 to 340mOsm/kg. An osmometer can be used to check and adjust the amount oftonicity adjusting agent to be added to obtain the desired osmolality.

As contemplated formulations are used as an ophthalmic formulation, itis generally preferred that the formulation also includes a viscositymodifier to adjust the viscosity of the formulation to a dynamicviscosity of between 5 and 50 cP (centipoise), and more preferablybetween 10 and 40 cP, and most preferably between 10 to 30 cP. Whilethere are numerous viscosity modifiers known in the art such as variouspolymers, glycerol, and polysaccharidic polymers (all of which arecontemplated herein), especially preferred viscosity modifiers includecellulosic viscosity modifiers. For example, particularly preferredcellulosic viscosity modifiers include modified and unmodifiedhydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropylmethylcellulose.

As will be readily appreciated, the exact quantity of the viscositymodifier may vary depending on the type of modifier used and desiredfinal viscosity. For example, where the viscosity modifier is acellulosic modifier and the final viscosity should be between 1 and 30cP, suitable quantities of the modifier will typically be in the rangeof 0.5 wt % (+/−0.1 wt %) of the ophthalmic atropine composition. Theperson of ordinary skill will be readily able to adjust the viscosity toa desired measure using viscometers (e.g., rotational, vibration, etc.)well known in the art.

In exemplary embodiments, suitable concentrations of the viscositymodifier in contemplated ophthalmic formulations may be any value lessthan 5% (w/w). For example, suitable concentrations of the viscositymodifier include 0.01% to 4.99% (w/w); or 0.05% to 4.50% (w/w), 0.10% to3.50% (w/w), 0.15% to 3.00% (w/w), 0.20% to 2.50% (w/w), 0.21% to 2.20%(w/w), 0.22% to 2.10% (w/w), 0.23% to 2.00% (w/w), 0.24% to 1.90% (w/w);0.25% to 1.80% (w/w), 0.26% to 1.70% (w/w), 0.27% to 1.60% (w/w), 0.28%to 1.50% (w/w), 0.29% to 1.40% (w/w), 0.30% to 1.30% (w/w), 0.31% to1.2% (w/w), 0.32% to 1.10% (w/w), 0.33% to 1.00% (w/w), 0.34% to 0.90%(w/w); 0.35% to 0.80% (w/w), 0.36% to 0.75% (w/w), 0.37% to 0.70% (w/w),0.38% to 0.69% (w/w), 0.39% to 0.68% (w/w), 0.40% to 0.67% (w/w), 0.41%to 0.66% (w/w), 0.42% to 0.65% (w/w), 0.43% to 0.64% (w/w), 0.44% to0.63% (w/w), 0.45% to 0.62% (w/w), 0.45% to 0.61% (w/w), 0.45% to 0.60%(w/w), 0.45% to 0.59% (w/w), 0.45% to 0.58% (w/w), 0.45% to 0.57% (w/w),0.45% to 0.56% (w/w), 0.45% to 0.55% (w/w), 0.46% to 0.54% (w/w), 0.47%to 0.53% (w/w), 0.48% to 0.52% (w/w) or 0.49% to 0.51% (w/w).

Therefore, appropriate concentrations of the viscosity modifier incontemplated ophthalmic formulations include 0.01%, 0.02%, 0.03%, 0.04%,0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%,0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%,0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%,0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%,0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%,0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%,0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%,0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%,0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%,0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.00%, 1.10%, 1.20%, 1.30%, 1.40%,1.50%, 1.60%, 1.70%, 1.80%, 1.90%, 2.00%, 2.10%, 2.20%, 2.30%, 2.40%,2.50%, 2.60%, 2.70%, 2.80%, 2.90%, 3.00%, 3.10%, 3.20%, 3.30%, 3.40%,3.50%, 3.60%, 3.70%, 3.80%, 3.90%, 4.00%, 4.10%, 4.20%, 4.30%, 4.40%,4.50%, 4.60%, 4.70%, 4.80%, 4.90% and 4.99% (w/w).

It should further be appreciated that contemplated compositions aresubstantially free of preservatives (i.e., preservatives not more than0.01 wt %, and more typically not more than 0.005 wt %). For example,preservatives that are typically not included are benzalkonium chloride,cetrimide or cetrimonium chloride or bromide, benzododecinium bromide,miramine, cetylpyridinium chloride, polidronium chloride orpolyquaternium-1, polyquaternium-42 (also known as polixetonium),sepazonium chloride; mercurial derivatives such as the phenylmercurysalts (acetate, borate or nitrate), mercuriothiolate sodium (otherwisecalled thiomersal or thimerosal) and mercurobutol; amidines such aschlorhexidine digluconate or polyhexamethylene biguanide (PHMB);alcohols such as chlorobutanol or phenylethanol or benzyl alcohol orphenol or m-cresol or phenoxyethanol; parabens or esters such asparahydroxybenzoic acid, methylparaben, and propylparaben).

Indeed, the inventors unexpectedly discovered that the formulationswithout preservatives had the same stability as with preservatives.

With respect to the sterilization of contemplated formulations it shouldbe appreciated that contemplated formulations may be sterilized usingall known manners of sterilization, including filtration through 0.22micron filters, heat sterilization, autoclaving, radiation (e.g., gamma,electron beam, microwave). Advantageously, and as is shown in moredetail below, the inventors have also discovered that contemplatedformulations can be compounded from two batches in which the viscosityagent is separately sterilized using high-pressure saturated steam at121° C. (for at least 5, or at least 10, or at least 15 minutes) fromthe atropine, buffer, and salt solution that was independently filtersterilized.

For example, in one preferred aspect of the inventive subject matter asdepicted in the FIGURE, the production of the ophthalmic solution isperformed using two distinct production tracks in which the viscositymodifier solution is separately prepared and sterilized from the drugsolution. Most notably, such process allowed for rapid and completedissolution of the atropine, tonicity, buffer components, and chelator,while also enabling a sterilization process that reduces or evenentirely eliminates thermal hydrolysis of atropine. Upon preparation ofthe sterile atropine solution, that solution can then be combined withthe viscosity modifier solution that was also sterilized. Whileconceptually sterilizable using filter sterilization as was the casewith the atropine solution, heat sterilization using an autoclave wasfound to help fully dissolve the viscosity modifier and render theviscous solution readily mixable with the drug solution. Viewed from adifferent perspective, it should therefore be appreciated that theseparate preparation and sterilization process avoided variousdifficulties that would be otherwise associated with single batchpreparation, including increased mixing time of the component todissolve buffer, tonicity agent, and chelator at increased agitation,increased sterile filtration time due to higher viscosity, etc.

Based on the so achieved stability, the combined solutions contemplatedherein can be further filtered through a particle filter (e.g., 40micron polypropylene filter), and filled in to a polyethylene,polypropylene or low-density polyethylene containers using preformedcontainers in single-use format or multi-dose format, or using ablow-fill-seal (BFS) process. BFS is a form of advanced asepticmanufacturing wherein the container is formed, filled, and sealed in onecontinuous, automated system not requiring human intervention. Theprocess begins with the extrusion of plastic granules in the form of ahot hollow pipe of molten plastic called a parison. The next step is theblow molding of the container with an open top through which thecontainer is filled, all while the plastic remains hot and in a moltenstate. Once filled, the container is hermetically sealed and cooled. Theblow-fill seal process can take several seconds, and contemplatedready-to-inject compositions advantageously are formulated to withstandthe temperature and pressure requirements without substantialdegradation of atropine (e.g., less than 5 wt %, less than 3 wt %, lessthan 2 wt %, less than 1 wt % degradation).

Once the atropine formulations are filled in large volume polymeric,semi-permeable infusion containers (e.g., BFS container, typically 1.0mL BFS ampoules), the containers can optionally be layered or coveredwith a secondary packaging system including an aluminum pouch.

The following examples are provided for illustrative purposes only andshould not be interpreted as limiting the present invention.

Examples

The following examples illustrate some of the experiments leading to theformulations according to the inventive subject matter, however, shouldnot be construed to limit the scope of the claims in any way.

Quantitative Analyses:

A combined test method based on Ultra Performance Liquid Chromatography(UPLC) was developed to perform identification, assay and determinationof related compounds in a single run. This was accomplished by using areversed-phase gradient UPLC with the UV detection including on-lineacquisition of UV absorption spectra. Octadecylsilyl-functionalizedsilica with sub-2 μm particles was used as a stationary phase forchromatographic analysis. The mobile phase is prepared by mixing anaqueous buffer solution with an acidic pH and an acetonitrile-watermixture. Quantification of the active ingredient and related compoundsis performed by comparing corresponding peak responses from a SampleSolution to the atropine peak response from a Standard solution.Relative response factors are used to correct for chemical structureeffects on the responses. Two identification methods are incorporatedinto this test method. Atropine is identified based on the retentiontime of the major peak in the Sample Solution chromatogram and on the UVabsorption spectrum acquired within this peak.

Exemplary Formulations and Stability Tests

Ophthalmic ready-to-use low-dose atropine formulations were preparedusing a two-step process substantially as shown in FIG. 1.

Step 1—Preparation of the Polymer Solution Phase: To about 60% of WFIthe required quantity of HPMC was added slowly and mixed until a clearsolution was observed. The solution was then subjected to autoclaving at121° C. for a period of about 30 min.

Step 2—Preparation of the Drug Solution Phase: To about 30% of WFI therequired quantities of disodium edetate, monobasic sodium phosphate,dibasic sodium phosphate and sodium chloride were added sequentiallyupon complete dissolution of each ingredient. The pH of the solution wasmeasured and adjusted to about 5.5±0.1 using hydrochloric acid/sodiumhydroxide. To the above solution atropine sulfate was added and mixeduntil there was complete dissolution.

The Drug Solution from Step 2 was then mixed with the Polymer Solutionin Step 1. The batch volume was made up using WFI to yield thepharmaceutical composition. Tables 1-3 provide exemplary formulationswith and without tonicity agent, with EDTA and low EDTA, and at varyingbuffer strengths.

TABLE 1 100 mM Buffer Composition 100 mM Buffer Composition (Low EDTA)No. Ingredient % w/v % w/v % w/v % w/v 1 Atropine Sulfate 0.01 0.01 0.010.01 2 Sodium Dihydrogen  0.059 0.06  0.059 0.06 Phosphate Anhydrous 3Disodium Hydrogen 1.15 1.16 1.15 1.16 Phosphate Anhydrous 4 EdetateSodium 0.10 0.10 0.01 0.01 5 Sodium Chloride — — — — 6 Hypromellose 29100.50 0.50 0.50 0.50 (Benecel ™ E4M Pharm1) 7 Hydrochloric Acid Q.S. forpH adjustment Q.S. for pH adjustment 8 Sodium Hydroxide Q.S. for pHadjustment Q.S. for pH adjustment 9 Water for Injection Q.S. to 100%Q.S. to 100%

TABLE 2 75 mM Buffer No Buffer Composition Composition with NaCl WithNaCl No. Ingredient % w/v % w/v % w/v % w/v 1 Atropine Sulfate 0.01 0.01 0.01 0.01 2 Sodium Dihydrogen 0.044 0.04 — — Phosphate Anhydrous 3Disodium Hydrogen 0.863 0.87 — — Phosphate Anhydrous 4 Edetate Sodium0.1 0.1 0.1 0.1  5 Sodium Chloride 0.15 0.15 0.9 0.91 6 Hypromellose2910 0.5 0.5 0.5 0.5  (Benecel ™ E4M Pharm1) 7 Hydrochloric Acid Q.S.for pH adjustment Q.S. for pH adjustment 8 Sodium Hydroxide Q.S. for pHadjustment Q.S. for pH adjustment 9 Water for Injection Q.S. to 100%Q.S. to 100%

TABLE 3 50 mM Buffer 50 mM Buffer 50 mM Buffer Composition CompositionComposition without NaCl with NaCl with NaCl, low EDTA No. Ingredient %w/v % w/v % w/v % w/v % w/v % w/v 1 Atropine Sulfate 0.01 0.01 0.01 0.010.01 0.01 2 Sodium Dihydrogen 0.0295 0.03 0.0295 0.03 0.0295 0.03Phosphate Anhydrous 3 Disodium Hydrogen 0.575 0.58 0.575 0.58 0.575 0.58Phosphate Anhydrous 4 Edetate Sodium 0.1 0.1 0.1 0.1 0.01 0.01 5 SodiumChloride — — 0.25 0.25 0.25 0.25 6 Hypromellose 2910 0.5 0.5 0.5 0.5 0.50.5 (Benecel ™ E4M Pharm1) 7 Hydrochloric Acid Q.S. for pH adjustmentQ.S. for pH adjustment Q.S. for pH adjustment 8 Sodium Hydroxide Q.S.for pH adjustment Q.S. for pH adjustment Q.S. for pH adjustment 9 Waterfor Injection Q.S. to 100% Q.S. to 100% Q.S. to 100%

Unless otherwise indicated, pharmaceutical compositions of Table 3 (50mM Buffer Composition with NaCl) were subjected to long term stabilitystudies. Lab scale batches of atropine sulfate ophthalmic solution weremanufactured, (approx. 0.4 mL) filled into 1 mL Blow-Fill-Seal (BFS)ampoules, and were further packaged in aluminum pouches. A number ofpouched ampoules were subjected to long term stability studies at 25°C.±2° C./60%±5% RH as per the International Committee on Harmonizationstability conditions (see URL: ich.org). Pouched ampoules subjected tothese long term stability studies were collected after 1 week, 2 weeks,3 weeks, 1 month, 2 months, and 3 months of stability storage, opened,and tested for levels of atropine sulfate, tropic acid, pH (whereapplicable) and viscosity (where applicable). Atropine and tropic acidlevels were measured using the UPLC method, and the results are shown inTables 4-8.

TABLE 4 100 mM buffered compositions Long term Stability (25° C./60% RH)Sample 1 2 3 1 2 3 Information Test Parameter Initial week weeks weeksmonth months months Assay of Atropine Sulfate 101.0 101.4 102.0 101.6101.5 101.0 100.6 Viscosity 23.15 — — — 24.00 — — pH 5.52 5.55 5.55 5.515.53 5.66 5.58 Tropic acid (RRT 0.88) ND 0.1 0.13 0.19 0.22 0.42 0.71Assay of Atropine Sulfate 104.2 103.4 103.3 103.2 101.3 102.4 — Tropicacid (RRT 0.88) ND 0.07 0.08 0.12 0.15 0.30 — Assay of Atropine Sulfate98.7 97.7 98 98.1 98 — — pH 5.55 5.40 5.41 5.42 5.43 — — Tropic acid(RRT 0.88) ND ND 0.07 0.09 0.12 — — Low EDTA Assay of Atropine Sulfate98.2 97.3 97.7 97.7 97.1 — — pH 5.55 5.40 5.40 5.41 5.42 — — Tropic acid(RRT 0.88) ND ND 0.31 0.1 0.12 — —

TABLE 5 75 mM buffered with NaCl Compositions Long term Stability (25°C./60% RH) Sample 2 3 1 2 3 Information Test Parameter Initial 1 weekweeks weeks month months months Assay of Atropine Sulfate 102.4 101.9101.7 101.5 101.3 101.0 — pH 5.28 — — — — — — Tropic acid (RRT 0.88) ND0.05 0.08 0.1 0.15 0.33 —

TABLE 6 50 mM buffered Without NaCl Compositions Long term Stability(25° C./60% RH) Sample 1 2 3 1 2 3 Information Test Parameter Initialweek weeks weeks month months months Assay of Atropine Sulfate 96.8 96.997.2 97.8 97.9 96.9 97.6 pH 5.38 5.32 5.23 — — — 5.38 Tropic acid (RRT0.88) ND 0.1 0.1 0.1 0.12 0.23 0.36 Low EDTA Assay of Atropine Sulfate96.1 95.9 95.6 95.6 95.9 — — pH 5.44 5.40 5.32 5.41 5.43 — — Tropic acid(RRT 0.88) ND ND ND 0.07 0.09 — —

TABLE 7 50 mM buffered with NaCl Compositions Long term Stability (25°C./60% RH) Sample 1 2 3 1 2 3 Information Test Parameter Initial weekweeks weeks month months months Assay of Atropine Sulfate 98.6 98.3 98.498.1 98 97.6 — pH 5.39 — — — — 5.36 — Tropic acid (RRT 0.88) ND 0.050.07 0.08 0.12 0.25 — Low EDTA Assay of Atropine Sulfate 98.8 98 98 9897.9 — — pH 5.41 5.31 5.32 5.35 5.33 — — Tropic acid (RRT 0.88) ND ND0.05 0.06 0.09 — —

TABLE 8 No Buffer Composition Long term Stability (20° C./60% RH) Sample1 2 3 1 2 3 Information Test Parameter Initial week weeks weeks monthmonths months Assay of Atropine Sulfate 103.7 103.0 103.0 103.0 102.4101.9 — pH — — — — — — — Tropic acid (RRT 0.88) ND 0.04 0.07 0.09 0.120.28 —

As can be readily seen from the above results, atropine solutions with areduced amount of buffering system concentration (75 mM, andparticularly 50 mM and less) had much lower levels of tropic acid(atropine degradation product) after already 1 month. Regressionanalysis was used to extrapolate the degradation levels at the end of 24months. Based on extrapolation methods commonly used in the art, the 50mM and no buffered concentrations have a shelf life of 18-24 months,which is 3-9 months beyond the 15 month extrapolated shelf life for the100 mM composition.

The above compositions were also subjected to accelerated stabilitystudies. Lab scale batches of atropine sulfate ophthalmic solution weremanufactured, (approx 0.4 mL) filled into 1 mL Blow-Fill-Seal (BFS)ampoules, and were further packaged in aluminum pouches. A number ofpouched ampoules were subjected to accelerated stability studies at 40°C.±2° C./75%±5% RH as per the International Committee on Harmonizationstability conditions. Pouched ampoules subjected to these acceleratedstability studies were collected after 1 week, 2 weeks, 3 weeks, 1month, 2 months, and 3 months of stability storage, opened, and testedfor levels of atropine sulfate, tropic acid viscosity (whereapplicable). Atropine and tropic acid levels were measured using theUPLC method, and the results are shown in Tables 9-13.

TABLE 9 100 mM buffered compositions Accelerated Stability (40° C./75%RH) Sample 1 2 3 1 2 3 Information Test Parameter Initial week weeksweeks month months months Assay of Atropine Sulfate 101.0 101.6 99.3101.1 100.0 97.5 95.2 Viscosity 23.15 — — — 19.96 — — pH 5.52 5.55 5.555.51 5.48 5.60 5.55 Tropic acid (RRT 0.88) ND 0.3 0.76 0.79 0.97 1.983.02 Assay of Atropine Sulfate 104.2 103.1 102.7 102.3 101.7 99.7 —Tropic acid (RRT 0.88) ND 0.19 0.35 0.57 0.67 1.52 — Assay of AtropineSulfate 98.7 97.6 97.4 97.1 95.6 — — pH 5.55 5.41 5.42 5.41 5.43 — —Tropic acid (RRT 0.88) ND 0.14 0.32 0.46 0.58 — — Low EDTA Assay ofAtropine Sulfate 98.2 97 96.9 96.7 96.3 — — pH 5.55 5.40 5.40 5.41 5.42— — Tropic acid (RRT 0.88) ND 0.16 0.31 0.45 0.58 — —

TABLE 10 75 mM buffered with NaCl compositions Accelerated Stability(40° C./75% RH) Sample 1 2 3 1 2 3 Information Test Parameter Initialweek weeks weeks month months months Assay of Atropine 102.4 101.5 101.0100.4 99.8 98.0 — Sulfate pH 5.28 — — — — — — Tropic acid (RRT 0.88) ND0.21 0.36 0.63 0.73 1.64 —

TABLE 11 50 mM buffered Without NaCl compositions Accelerated Stability(40° C./75% RH) Sample 1 2 3 1 2 3 Information Test Parameter Initialweek weeks weeks month months months Assay of Atropine Sulfate 96.8 9797.5 97.6 96.9 108.6 95.1 pH 5.38 5.31 5.25 — — — 5.37 Tropic acid (RRT0.88) ND 0.2 0.3 0.4 0.55 1.16 1.67 Low EDTA Assay of Atropine Sulfate96.1 95.1 95.3 94.9 95.2 — — pH 5.44 5.37 5.41 5.36 5.37 — — Tropic acid(RRT 0.88) ND 0.1 0.21 0.31 0.42 — —

TABLE 12 50 mM buffered with NaCl compositions Accelerated Stability(40° C./75% RH) Sample 1 2 3 1 2 3 Information Test Parameter Initialweek weeks weeks month months months Assay of Atropine Sulfate 98.6 98.197.7 97.2 97.2 95.6 — pH 5.39 — — — — 5.42 — Tropic acid (RRT 0.88) ND0.15 0.26 0.39 0.5 1.12 — Low EDTA Assay of Atropine Sulfate 98.8 97.697.3 97.1 97.1 — — pH 5.41 5.33 5.35 5.32 5.34 — — Tropic acid (RRT0.88) ND 0.09 0.23 0.34 0.45 — —

TABLE 13 No Buffer Composition Accelerated Stability (40° C./75% RH)Sample 1 2 3 1 2 3 Information Test Parameter Initial week weeks weeksmonth months months Assay of Atropine Sulfate 103.7 102.9 102.4 102.2101.7 99.9 — pH — — — — — — — Tropic acid (RRT 0.88) ND   0.15   0.26 0.4   0.51  1.17 —

Once more, it can be readily taken from the data that atropine solutionswith a reduced amount of buffering system concentration (75 mM, andparticularly 50 mM and less) had much lower levels of tropic acid(atropine degradation product) after already 1 month. Regressionanalysis was utilized to extrapolate the degradation levels at the endof 24 months. Based on extrapolation methods commonly used in the art,the 50 mM and no buffered concentrations will have a shelf life of 18-24months, which is 3-9 months beyond the 15 month extrapolated shelf lifefor the 100 mM composition.

Additional Stability Studies using further variations in compositionagain established that lower buffer strength, especially with a twocomponent buffer system provide increased stability of the ophthalmiclow-dose atropine formulations having compositions as shown in Tables14-15 at both normal and accelerated storage conditions below (resultsshown in Tables 16-19.

TABLE 14 Lot: RD-019-020 Lot: RD-019-023 Lot: RD-001-185 No. Ingredientmg/mL mg/mL mg/mL 1 Atropine Sulfate 0.1 0.1 0.1 Monohydrate 2 MonobasicSodium 0.59 0.59 0.442 Phosphate Anhydrous 3 Dibasic Sodium 11.5 11.58.63 Phosphate Anhydrous 4 Edetate Disodium Dihydrate 1.0 0.1 1.0 5Sodium Chloride — — 1.5 6 Hypromellose 2910 5.0 5.0 5.0 (Benecel E4MPharm) 7 Hydrochloric Acid q.s. for pH adjustment q.s. for pH adjustmentq.s. for pH adjustment 8 Sodium Hydroxide q.s. for pH adjustment q.s.for pH adjustment q.s. for pH adjustment 9 Water for Injection q.s. to100% q.s. to 100% q.s. to 100%

TABLE 15 Lot: RD-019-026 Lot: RD-019-029 Lot: RD-001-179 S. No.Ingredient mg/mL mg/mL mg/mL 1 Atropine Sulfate 0.1 0.1 0.1 Monohydrate2 Monobasic Sodium 0.295 0.295 — Phosphate Anhydrous 3 Dibasic SodiumPhosphate 5.75 5.75 — Anhydrous 4 Edetate Disodium Dihydrate 1.0 0.1 1.05 Sodium Chloride — 2.5 9.0 6 Hypromellose 2910 5.0 5.0 5.0 (Benecel E4MPharm) 7 Hydrochloric Acid q.s. for pH adjustment q.s. for pH adjustmentq.s. for pH adjustment 8 Sodium Hydroxide q.s. for pH adjustment q.s.for pH adjustment q.s. for pH adjustment 9 Water for Injection q.s. to100% q.s. to 100% q.s. to 100%

TABLE 16 Various formulations Accelerated Stability (40° C./75% RH) 1 23 1 2 3 Lot Number Test Parameter Initial week weeks weeks month monthsmonths Lot: pH 5.55 5.41 5.42 5.41 5.43 5.37 5.32 RD-019-020 Assay ofAtropine Sulfate 98.7 97.6 97.4 97.1 95.6 95.8 94.4 (%) Related Tropicacid ND 0.14 0.32 0.46 0.58 1.45 2.20 Compounds Unknown ND 0.19 0.240.24 0.25 0.26 0.2 (%) (RRT = 1.21) Apoatropine ND ND 0.05 0.06 0.060.12 0.17 Total ND 0.3 0.6 0.8 0.9 1.8 2.6 impurities Lot: pH 5.55 5.405.40 5.41 5.42 5.36 5.32 RD-019-023 Assay of Atropine Sulfate 98.2 9796.9 96.7 96.3 95.2 94.3 (%) Related Tropic acid ND 0.16 0.31 0.45 0.581.41 2.14 Compounds Unknown ND 0.18 0.22 0.23 0.24 0.24 0.23 (%) (RRT =1.21) Apoatropine ND ND 0.04 0.06 0.06 0.13 0.16 Total ND 0.3 0.6 0.70.9 1.8 2.5 Impurities Lot: pH 5.28 NT NT NT NT 5.46 NT RD-001-185 Assayof Atropine Sulfate 102.4 101.5 101.0 100.4 99.8 98.0 96.2 (%) RelatedTropic acid ND 0.21 0.36 0.63 0.73 1.64 2.43 Compounds Unknown ND 0.230.25 0.25 0.25 0.25 0.25 (%) (RRT = 1.21) Apoatropine ND 0.04 0.05 0.060.07 0.12 0.17 Total ND 0.5 0.7 0.9 1.1 2.0 2.9 Impurities

TABLE 17 Various formulations Long term Stability (25° C./60% RH) 2 3 12 3 Lot Number Test Parameter Initial 1 week weeks weeks month monthsmonths Lot: pH 5.55 5.40 5.41 5.42 5.43 5.37 5.32 RD-019-020 Assay ofAtropine Sulfate (%) 98.7 97.7 98 98.1 98 98.1 98.6 Related Tropic acidND ND 0.07 0.09 0.12 0.29 0.44 Compounds Unknown ND ND 0.1 0.11 0.140.21 0.2 (%) (RRT = 1.21) Apoatropine ND ND ND ND ND ND 0.04 Totalimpurities ND ND 0.2 0.2 0.3 0.5 0.7 Lot: pH 5.55 5.40 5.40 5.41 5.425.36 5.31 RD-019-023 Assay of Atropine Sulfate (%) 98.2 97.3 97.7 97.797.1 98.0 97.8 Related Tropic acid ND ND 0.31 0.1 0.12 0.28 0.43Compounds Unknown ND ND 0.22 0.1 0.12 0.19 0.2 (%) (RRT = 1.21)Apoatropine ND ND ND ND ND ND 0.03 Total Impurities ND ND 0.2 0.2 0.20.5 0.7 Lot: pH 5.28 NT NT NT NT 5.49 NT RD-001-185 Assay of AtropineSulfate (%) 102.4 101.9 101.7 101.5 101.3 101.0 100.6 Related Tropicacid ND 0.05 0.08 0.1 0.15 0.33 0.48 Compounds Unknown ND ND 0.1 0.130.16 0.21 0.23 (%) (RRT = 1.21) Apoatropine ND ND ND ND ND ND 0.04 TotalImpurities ND 0.1 0.2 0.2 0.3 0.5 0.7

TABLE 18 Various formulations Accelerated Stability (40° C./75% RH) 1 23 1 2 3 Lot Number Test Parameter Initial week weeks weeks month monthsmonths Lot: pH 5.44 5.37 5.41 5.36 5.37 5.35 5.37 RD-019-026 Assay ofAtropine Sulfate 96.1 95.1 95.3 94.9 95.2 94.3 93.8 (%) Related Tropicacid ND 0.1 0.21 0.31 0.42 1.00 1.53 Compounds Unknown ND 0.15 0.2 0.210.23 0.25 0.24 (%) (RRT = 1.21) Apoatropine ND ND 0.04 0.05 0.06 0.100.15 Total ND 0.3 0.5 0.6 0.7 1.4 1.9 Impurities Lot: pH 5.41 5.33 5.355.32 5.34 5.30 5.24 RD-019-029 Assay of Atropine Sulfate 98.8 97.6 97.397.1 97.1 97.5 95.6 (%) Related Tropic acid ND 0.09 0.23 0.34 0.45 1.081.68 Compounds Unknown ND 0.15 0.19 0.21 0.21 0.22 0.24 (%) (RRT = 1.21)Apoatropine ND ND 0.05 0.05 0.06 0.10 0.15 Total ND 0.2 0.5 0.6 0.7 1.42.0 Impurities Lot: pH 5.52 NT NT NT NT 5.58 NT RD-001-179 Assay ofAtropine Sulfate 103.7 102.9 102.4 102.2 101.7 99.9 99.0 (%) RelatedTropic acid ND 0.15 0.26 0.4 0.51 1.17 1.78 Compounds Unknown ND 0.250.28 0.28 0.28 0.29 0.29 (%) (RRT = 1.21) Apoatropine ND ND 0 0.05 0.050.08 0.11 Total ND 0.4 0.5 0.7 0.8 1.5 2.2 Impurities

TABLE 19 Various formulations Long term Stability (25° C./60% RH) 1 2 31 2 3 Lot Number Test Parameter Initial week weeks weeks month monthsmonths Lot: pH 5.44 5.40 5.32 5.41 5.43 5.31 5.30 RD-019-026 Assay ofAtropine Sulfate 96.1 95.9 95.6 95.6 95.9 96.2 96.5 (%) Related Tropicacid ND ND ND 0.07 0.09 0.21 0.32 Compounds Unknown ND ND ND ND 0.110.18 0.20 (%) (RRT = 1.21) Apoatropine ND ND ND ND ND ND ND Total ND NDND 0.1 0.2 0.4 0.5 Impurities Lot: pH 5.41 5.31 5.32 5.35 5.33 5.26 5.25RD-019-029 Assay of Atropine Sulfate 98.8 98 98 98 97.9 98.0 98.5 (%)Related Tropic acid ND ND 0.05 0.06 0.09 0.22 0.32 Compounds Unknown NDND ND ND 0.1 0.17 0.2 (%) (RRT = 1.21) Apoatropine ND ND ND ND ND ND NDTotal ND ND 0.1 0.1 0.2 0.4 0.5 Impurities Lot: pH 5.52 NT NT NT NT 5.45NT RD-001-179 Assay of Atropine Sulfate 103.7 103.0 103.0 103.0 102.4101.9 102.2 (%) Related Tropic acid ND 0.04 0.07 0.09 0.12 0.28 0.39Compounds Unknown ND 0.09 0.14 0.16 0.2 0.26 0.28 (%) (RRT = 1.21)Apoatropine ND ND ND ND ND ND ND Total ND 0.1 0.2 0.3 0.3 0.5 0.7Impurities

The effect of pH and stability of compositions of Table 20 was testedand exemplary test results for pH 3.5 and pH 6.0 are provided in theTables 21-22 (pH 3.5) and Tables 23-24 (pH 6.0) below.

TABLE 20 No. Ingredient Qty/mL 1 Atropine Sulfate Monohydrate 0.1 mg 2Sodium Dihydrogen 0.295 mg Phosphate Anhydrous 3 Disodium Hydrogen 5.75mg Phosphate Anhydrous 4 Edetate Disodium Dihydrate 0.1 mg 5Hypromellose 2910, 5.0 mg Benecel E4M Pharm 6 Hydrochloric Acid pHadjustment to 3.5 or 6.0 7 Sodium Hydroxide pH adjustment to 3.5 or 6.08 Water for Injection q.s.

TABLE 21 Accelerated Stability (40° C./75% RH) Test Parameter Initial 2weeks 1 month 2 months 3 months 6 months Appearance Clear, Clear, Clear,Clear, Clear, Clear, colorless colorless colorless colorless colorlesscolorless solution solution solution solution solution solution pH 3.563.52 3.54 3.56 3.47 3.70 Assay of Atropine Sulfate (%) 99.5 99.4 98.798.2 98.6 97.9 Related Tropic acid ND ND ND 0.14 0.20 0.41 Compounds (%)Unknown ND ND ND 0.07 0.07 0.11 (RRT = 1.21) Apoatropine ND ND ND 0.060.08 0.13 Unknown (RRT ND ND ND ND 0.10 ND 0.508) Unknown (RRT ND ND NDND ND 0.20 0.683) Total Impurities ND ND ND 0.3 0.4 0.6

TABLE 22 Accelerated Stability (25° C./60% RH) Test Parameter Initial 2weeks 1 month 2 months 3 months 6 months Appearance Clear, Clear, Clear,Clear, Clear, Clear, colorless colorless colorless colorless colorlesscolorless solution solution solution solution solution solution pH 3.563.52 3.53 3.58 3.46 3.70 Assay of Atropine Sulfate (%) 99.5 99.2 98.998.7 98.9 98.9 Related Tropic acid ND ND ND ND ND 0.09 Compounds (%)Unknown ND ND ND ND ND ND (RRT = 1.21) Apoatropine ND ND ND ND ND NDUnknown (RRT ND ND ND ND ND ND 0.508) Unknown (RRT ND ND ND ND ND ND0.683) Total Impurities ND ND ND ND ND 0.1

TABLE 23 Accelerated Stability (40° C./75% RH) Test Parameter Initial 2weeks 1 month 2 months 3 months 6 months Appearance Clear, Clear, Clear,Clear, Clear, Clear, colorless colorless colorless colorless colorlesscolorless solution solution solution solution solution solution pH 5.995.87 5.89 5.83 5.83 6.00 Assay of Atropine Sulfate (%) 108.5 106.7 104.199.1 95.3 84.2 Related Tropic acid ND 0.90 1.91 4.17 6.07 11.26Compounds Unknown ND 0.32 0.32 0.29 0.29 0.27 (%) (RRT = 1.21)Apoatropine ND 0.06 0.09 0.18 0.25 0.42 Total ND 1.3 2.3 4.6 6.6 12.0Impurities

TABLE 24 Accelerated Stability (25° C./60% RH) Test Parameter Initial 2weeks 1 month 2 months 3 months 6 months Appearance Clear, Clear, Clear,Clear, Clear, Clear, colorless colorless colorless colorless colorlesscolorless solution solution solution solution solution solution pH 5.995.87 5.68 5.69 5.82 6.00 Assay of Atropine Sulfate (%) 108.5 108.5 107.1106.0 105.5 103.1 Related Tropic acid ND 0.19 0.39 0.85 1.21 2.43Compounds Unknown ND 0.21 0.25 0.29 0.29 0.29 (%) (RRT = 1.21)Apoatropine ND ND ND 0.05 0.05 0.08 Total ND 0.4 0.6 1.2 1.6 2.8Impurities

Atropine sulfate ophthalmic solution is intended to be provided as asingle or multi-dose product for topical administration to the eye,which can advantageously be provided as a Blow/Fill/Seal (BFS) ampule asthe primary container closure system. For example, suitable ampulematerials include Lyondellbasell Purell PE 3020 D resin, which wastested as follows:

Compositions as shown in Table 3 (50 mM Buffer Composition with NaCl,low EDTA), filled in BFS ampoules were tested at concentrations of 0.01%(w/v) and 0.02% (w/v) under accelerated (40° C./75% RH) and long-term(25° C./60% RH) storage conditions. The filled BFS ampoules were thenpackaged into a secondary packaging (here: laminated pouch) for storageas indicated. The results of this study are presented in Tables 25-28.

TABLE 25 Atropine Concentration 0.01 wt % Accelerated Storage (40°C./75% RH) Test Parameter Initial 2 weeks 1 month 2 months 3 months 6months Appearance Clear, Clear, Clear, Clear, Clear, Clear, colorlesscolorless colorless colorless colorless colorless solution solutionsolution solution solution solution pH 5.49 5.49 5.39 5.42 5.63 5.47Viscosity (cPs) 19.96 NA NA NA 20.48 19.48 Assay of Atropine Sulfate (%)104.2 104.6 102.0 102.5 99.4 93.0 Related Tropic acid NR 0.41 0.89 1.732.66 4.67 Compounds Apoatropine NR NR 0.04 0.09 0.14 0.23 (%) Totalimpurities NR 0.41 0.93 1.82 2.80 4.90

TABLE 26 Atropine Concentration 0.01 wt % Long-Term Storage (25° C./60%RH) Test Parameter Initial 2 weeks 1 month 2 months 3 months 6 monthsAppearance Clear, Clear, Clear, Clear, Clear, Clear, colorless colorlesscolorless colorless colorless colorless solution solution solutionsolution solution solution pH 5.49 5.50 5.44 5.43 5.67 5.45 Viscosity(cPs) 19.96 NA NA NA 20.56 19.42 Assay of Atropine Sulfate (%) 104.2105.8 103.7 105.9 103.3 105.2 Related Tropic acid NR 0.11 0.20 0.35 0.531.06 Compounds Apoatropine NR NR NR NR NR 0.05 (%) Total Impurities NR0.11 0.20 0.35 0.53 1.11

TABLE 27 Atropine Concentration 0.02 wt % Accelerated Storage (40°C./75% RH) Test Parameter Initial 2 weeks 1 month 2 months 3 months 6months Appearance Clear, Clear, Clear, Clear, Clear, Clear, colorlesscolorless colorless colorless colorless colorless solution solutionsolution solution solution solution pH 5.35 5.43 5.33 5.36 5.57 5.34Viscosity (cPs) 20.26 NA NA NA 21.20 19.82 Assay of Atropine Sulfate (%)105.5 106.0 104.0 103.1 102.6 95.6 Related Tropic acid NR 0.31 0.70 1.261.99 3.73 Compounds Apoatropine NR NR 0.13 0.09 0.13 0.24 (%) TotalImpurities NR 0.31 0.83 1.35 2.12 3.97

TABLE 28 Atropine Concentration 0.02 wt % Long-Term Storage (25° C./60%RH) Test Parameter Initial 2 weeks 1 month 2 months 3 months 6 monthsAppearance Clear, Clear, Clear, Clear, Clear, Clear, colorless colorlesscolorless colorless colorless colorless solution solution solutionsolution solution solution pH 5.35 5.42 5.33 5.38 5.57 5.34 Viscosity(cPs) 20.26 NA NA NA 21.17 20.17 Assay of Atropine Sulfate (%) 105.5106.2 105.4 105.8 104.9 101.8 Related Tropic acid NR 0.06 0.14 0.24 0.380.76 Compounds Apoatropine NR NR NR NR NR NR (%) Total Impurities NR0.06 0.14 0.24 0.34 0.76

As used in the description herein and throughout the claims that follow,the meaning of “a,” “an,” and “the” includes plural reference unless thecontext clearly dictates otherwise. Also, as used in the descriptionherein, the meaning of “in” includes “in” and “on” unless the contextclearly dictates otherwise.

In some embodiments, the numbers expressing quantities of ingredients,properties such as concentration, reaction conditions, and so forth,used to describe and claim certain embodiments of the invention are tobe understood as being modified in some instances by the term “about.”Accordingly, in some embodiments, the numerical parameters set forth inthe written description and attached claims are approximations that canvary depending upon the desired properties sought to be obtained by aparticular embodiment. In some embodiments, the numerical parametersshould be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques. Notwithstandingthat the numerical ranges and parameters setting forth the broad scopeof some embodiments of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspracticable. The numerical values presented in some embodiments of theinvention may contain certain errors necessarily resulting from thestandard deviation found in their respective testing measurements.

It should be apparent, however, to those skilled in the art that manymore modifications besides those already described are possible withoutdeparting from the inventive concepts herein. The inventive subjectmatter, therefore, is not to be restricted except in the spirit of thedisclosure. One skilled in the art will recognize many methods andmaterials similar or equivalent to those described herein, which couldbe used in the practice of the present invention. Indeed, the presentinvention is in no way limited to the methods and materials described.

Moreover, in interpreting the disclosure all terms should be interpretedin the broadest possible manner consistent with the context. Inparticular the terms “comprises” and “comprising” should be interpretedas referring to the elements, components, or steps in a non-exclusivemanner, indicating that the referenced elements, components, or stepscan be present, or utilized, or combined with other elements,components, or steps that are not expressly referenced.

What is claimed is:
 1. A method of increasing storage stability ofatropine in a liquid low-dose ophthalmic formulation, comprising:formulating an aqueous solution with a low-strength buffer system thatincludes a first and second buffer component, wherein the low-strengthbuffer system has a concentration of equal or less than 75 mM buffer;including into the aqueous solution a pharmaceutically acceptable salt,a viscosity modifier, and a chelator; including into the aqueoussolution atropine or a pharmaceutically acceptable salt thereof at a lowdose, wherein the low dose is equal or less than 0.05 wt % of theophthalmic formulation; adjusting pH of the ophthalmic formulation to apH between 5 and 6; and wherein the ophthalmic formulation after storageover at least two months at 25° C. and 60% relative humidity containsequal or less than 0.35% tropic acid formed from degradation of theatropine.
 2. The method of claim 1, wherein the first and second buffercomponents are monobasic and dibasic sodium phosphate, respectively. 3.The method of claim 1, wherein the low-strength buffer system has aconcentration of equal or less than 50 mM buffer.
 4. The method of claim1, wherein the pharmaceutically acceptable salt is sodium chloride andwherein the salt is present in the ophthalmic atropine composition in anamount of 0.5 wt % (+/−0.2 wt %) of the ophthalmic formulation.
 5. Themethod of claim 1, wherein the chelator is selected from the groupconsisting of a bicarboxylic acid, a tricarboxylic acid, and anaminopolycarboxylic acid.
 6. The method of claim 5, wherein the chelatoris ethylenediaminetetraacetic acid (EDTA).
 7. The method of claim 1,wherein the chelator is present in an amount of 0.01 wt % (+/−20% abs.)of the ophthalmic formulation.
 8. The method of claim 1, wherein theviscosity modifier is a cellulosic viscosity modifier.
 9. The method ofclaim 8, wherein the cellulosic viscosity modifier is a hydroxyethylcellulose, a hydroxypropyl cellulose, or a hydroxypropylmethylcellulose.
 10. The method of claim 8, wherein the cellulosicviscosity modifier is present in an amount of 0.5 wt % (+/−0.1 wt %) ofthe ophthalmic formulation.
 11. The method of claim 8, wherein thecellulosic viscosity modifier is prepared as a separate solution, andcombined with the aqueous solution containing the buffer system, thepharmaceutically acceptable salt, the viscosity modifier, the chelator,and the atropine or the pharmaceutically acceptable salt thereof. 12.The method of claim 1, wherein the low dose is between 0.01 wt % and0.02 wt % of the ophthalmic formulation.
 13. The method of claim 1,wherein the low dose is between 0.001 wt % and 0.01 wt % of theophthalmic formulation.
 14. The method of claim 1, wherein the low doseis equal or less than 0.01 wt % of the ophthalmic formulation.
 15. Themethod of claim 1, wherein aqueous solution is formulated usingdeoxygenated water.
 16. The method of claim 1, wherein the pH is between5.5 (+/−0.2) and 6.0 (+/−0.2).
 17. The method of claim 1, wherein theatropine or a pharmaceutically acceptable salt thereof is atropinesulfate.
 18. The method of claim 1, further comprising a step ofsterilizing the ophthalmic formulation.
 19. The method of claim 18,wherein the step of sterilizing comprises sterile filtration.
 20. Themethod of claim 1, further comprising a step of filling the ophthalmicformulation into a multi-dose container.